1. Field of the Invention
This invention relates to a ball valve, more particularly to a ball valve adapted to couple with an output drive shaft of a valve control device.
2. Description of the Related Art
Referring to FIGS. 1 and 2, a conventional ball valve 10 is shown to include a valve body 11 with a fluid passage 111 to form an inlet 112 and an outlet 113 at two opposite sides thereof, and a valve ball 19 which is disposed in the passage 111 and which is rotated to control the fluid communication between the inlet 112 and the outlet 113. A hollow housing 12 is provided on the valve body 11, and has an upper mounting plate portion 122 with screw holes 123 and an upwardly extending hole 121 that is fluidly communicated with the passage 111 for surrounding an upright stem 13. The stem 13 has one end coupled to the valve ball 19 and the other end extending through the housing 12 for coupling with an output drive shaft (not shown) of a valve control device 20 via a coupler 31. A plurality of sealing rings 14,15 are press-fitted by a resilient ring 16 in the hole 121 so as to be interposed between the stem 13 and the inner peripheral wall of the housing 12 in order to prevent spilling from the valve body 11. A screw nut 18 and a bearing plate 17 are mounted rotatably on the stem 13. A connecting bracket 30 has upper and lower side walls with screw holes 33,35 so that a plurality of screws 32,34 can be engaged threadedly in the screw holes 33,21 and 35,123 to interengage the valve control device 20 and the housing 12.
Since the resilient ring 16, the bearing plate 17 and the screw nut 18 are mounted outwardly of the housing 12, the connecting bracket 30 is needed to facilitate interconnection between the ball valve 10 and the valve control device 20, thereby increasing the manufacturing cost. In addition, the ball valve 10 and the valve control device 20 are threaded respectively on the connecting bracket 30, thereby resulting in the need for a large number of screws 32,34.